to pleasure a women's nether-regions by rotating the 5 fingers on ure right hand in a tickling like motion while blowing a steady stream of air and flapping ure left hand through the air stream to create a copter sound. try it sometime...

when a girl with no legs (just stubs) has sex with you, they will get on top of you, you penetrate her, she gets up perpendicular to you on the bottom, than she rotates/spins around your dick in her vagina while bouncing...

"That girl in the wheelchair over their gave me a ROFL copter last night!"

ROFL Copter is when someone is sitting on a computer chair, such as the one i am in right now, that rotates about at the stem. A ROFL Copter is when you laugh so hard, you actually spin out of the chair.